1. Field
The present invention relates to automotive vehicle instrumentation and, more particularly, to instrumentation for sensing and indicating inclination of the vehicle.
2. Related Art
Some automotive vehicles may have a propensity to rollover under certain adverse driving conditions, such as when in an aggressive turn or on a steep incline. This is primarily due to their high center of gravity. Automotive engineers have been challenged by consumer demands to produce vehicles having a high center of gravity (such as sport utility vehicles) while reducing or eliminating the propensity of these vehicles to rollover.
At the same time, drivers of these vehicles tend to acclimate to the vehicle""s behavior under various driving conditions, thereby decreasing the potential for driver-induced rollovers. However, this may not always be the case. For example, in multi-vehicle households, wherein one vehicle is a sport utility vehicle and the other is either a sports car or a sedan, the driver may not be immediately conditioned to the degree of responsiveness of each vehicle. In this respect, sports cars typically have exceptional handling around sharp curves, due to their low center of gravity; whereas, sport utility vehicles do not. As a result, driving style enjoyed in the sports car may have adverse effects if used in the sport utility vehicle.
Therefore, systems have been developed to provide information to the driver about a vehicle""s inclination. One example of such a system is described in U.S. Pat. No. 5,825,284. This system includes multiple sensors mounted at multiple structural locations on the vehicle, resulting in a relatively complex detection and indication system.
The present invention is a simple device and a method used to provide information about vehicle inclination and conditions that would indicate the potential of a rollover. The device and method may be embodied in original equipment or in an aftermarket product that allows the driver to readily and easily determine the vehicle""s inclination. The device and method may also be used to warn of a possible rollover condition. The device and method may also utilize the inclination information to indicate a corrected heading of the vehicle.
In one embodiment of the invention, a mirror assembly for use in a vehicle is disclosed. The mirror assembly includes a frame, a mirror mounted to the frame and an indicator mounted to the frame. The indicator communicates directly or indirectly with a sensor that is responsive to at least one of pitch angle and roll angle of the vehicle. The indicator indicates the at least one of pitch angle and roll angle.
In another embodiment, a multiple use mirror assembly for use in a motor vehicle is disclosed. The mirror assembly includes a mirror frame having a mirror fixed thereto and means for adjustably securing the mirror frame to the motor vehicle. The mirror assembly also includes an indicator integrally secured to the mirror assembly and simultaneously visible with reflections in the mirror. At least one sensor for sensing at least one of pitch angle and roll angle of the motor vehicle independently of the relative position of the mirror frame and mirror relative to the vehicle is operatively connected to the indicator. The indicator indicates the sensed at least one of pitch angle and roll angle of the vehicle.
In another embodiment, an apparatus for detecting inclination of a vehicle is disclosed. The apparatus includes a controller and a sensor communicating with the controller. This sensor is responsive to at least one of pitch angle and roll angle of the vehicle. The controller calculates a rate of change of the at least one of pitch angle and roll angle based on the at least one of pitch angle and roll angle of the vehicle sensed by the sensor.
In yet another embodiment, a method of detecting inclination of a vehicle is disclosed. The method includes sensing at least one of pitch angle and roll angle of the vehicle, and calculating a rate of change of the at least one of pitch angle and roll angle.
In still another embodiment, a method of detecting inclination of a vehicle is disclosed. The method includes sensing at least one of pitch angle and roll angle of the vehicle, comparing the at least one of sensed pitch angle and roll angle to at least one threshold, and comparing the at least one of sensed pitch angle and roll angle to a different threshold based upon vehicle operating conditions.
In yet another embodiment, a method of reducing false alarms in a device for detecting inclination of a vehicle is disclosed. The method includes sensing at least one of pitch angle and roll angle of the vehicle, calculating a rate of change of the at least one pitch angle and roll angle of the vehicle, and warning only if the rate of change of the at least one of pitch angle and roll angle of the vehicle exceeds a first threshold value and does not exceed a second threshold value.
In another embodiment, a device in a vehicle is disclosed. The vehicle has a vehicle plane defined by the plane through which the rotational axes of the wheels of the vehicle pass. The device includes a sensor for sensing lateral acceleration of the vehicle in the vehicle plane. The device also includes a controller communicating with the sensor. The controller calculates a rate of change of the lateral acceleration and compares the calculated rate of change to a threshold. The device further includes an indicator communicating directly or indirectly with the controller. The indicator indicates a warning when the calculated rate of change exceeds the threshold.
In another embodiment, a method of detecting inclination of a vehicle is disclosed. The method includes sensing at least one of pitch angle and roll angle of the vehicle to provide a static signal; calculating a rate of change of the at least one of pitch angle and roll angle to provide a transient parameter; combining the static signal and the transient signal to provide a combined inclination parameter; and, comparing the combined inclination parameter to a threshold.
In another embodiment, a mirror assembly for use in a vehicle is disclosed. The mirror assembly includes a frame and a mirror mounted to the frame. A compass is coupled to the frame. The compass detects a heading of the vehicle. The compass communicates with a controller that communicates with a sensor that is responsive to at least one of pitch angle and roll angle of the vehicle. The controller corrects the detected heading of the vehicle based on the sensed at least one of pitch angle and roll angle of the vehicle. An indicator is mounted to the frame. The indicator indicates the corrected heading.
Various embodiments of the present invention provide certain advantages and overcome certain drawbacks of prior devices and systems. Embodiments of the invention may not share the same advantages and those that do may not share them under all circumstances.
Further features and advantages of the present invention as well as the structure and method of making various embodiments of the present invention are described in detail below with reference to the accompanying drawings.